The present invention relates in general to rotary printing presses and, in particular, to a new and useful office offset printing press, equipped with an inking mechanism comprising a closed ink fountain and a fountain roller which is driven for rotary motion and which segmentally projects into the fountain, and by which the ink is removed in metered quantities and transferred to a spreader roller which is operatively connected to the plate cylinder by means of a contacting application roller which can be applied to the plate cylinder.